Some books are serials, not to be mistaken for anything else. The Two Towers, for example, ought never to be read in isolation. That’s perhaps a pretty fair description for any middle book of a trilogy. It’s not just books, of course. The Empire Strikes Back had an unsatisfying conclusion—because it didn’t conclude anything.
Am I suggesting that no one ever read The Two Towers or watch The Empire Strikes Back? Of course not (so douse the torches and put away the pitchforks). Hopefully readers/viewers know up front that these are middles of trilogies so they can make an informed decision. (Ever accidentally read a book or view a movie out of sequence and suffer great frustration as a result? Ever buy a book only to discover it’s the middle or end of a trilogy and others are out of print? At least nowadays those earlier books are usually available, if only secondhand, somewhere on the Internet.)
Contrariwise, as Tweedledee might say, readers/viewers should also know when something isn’t part of a serial. The distinction I’m trying to delineate is between serials (a three-book serial being, of course, a trilogy) and series.
Some stories are serials from birth. I presume LoTR was a always meant to be a serial because The Fellowship of the Ring ends with nothing resolved. I suspect Peter F. Hamilton’s Night’s Dawn “trilogy” (six thick tomes, outdoing the Hitchhiker‘s “trilogy”) was planned from the start as an extended serial arc. And Philip Jose Farmer’s Riverworld series. Ditto Harry Turtledove’s Worldwar books—it’s nice to get to the end of the war! (And your favorite addition to the list?)
Of course, self-contained books and movies can morph into serials. Star Wars (the original, become known as episode IV), was a fun, totally self-contained movie. Star Wars was so successful that when Spielberg and Lucas did The Empire Strikes Back, they had no need to make it self-contained. They (and the viewing public) could be confident that the story arc would be completed with a third movie. Likewise, Back to the Future was standalone. With the follow-on movies it became a trilogy, and Back to the Future Part II explicitly ends with the words “To be continued” (or some such).
Asimov’s Foundation was a synthesis of designed-to-be-standalone novelettes; not surprisingly the collection stands alone well. Not so (for me, in any event) Foundation and Empire, which somewhat entails a mysterious Second Foundation. Readers don’t know what that mysterious entity is until the third book, (appropriately enough named) Second Foundation.
At the opposite end of the multi-book (or -movie) spectrum are novels and films that—although related by characters or setting—stand alone perfectly well. Terry Pratchett’s Discworld books. Harry Harrison’s Deathworld books. Fred Saberhagen’s Dracula books. Switching genres for a moment, C. S. Forester’s Horatio Hornblower books and stories. The Die Hard, Indiana Jones, and James Bond movie series. (Again, weigh in with your favorites.)
Readers and viewers will differ about what’s totally standalone, what’s totally serially dependent, and what’s merely enriched by reading/viewing in a particular order.
What’s my point? Caveat emptor. Look for overt series indications. Check out the “other books by” pages. But also know that some reviewers are (too) fast to label any second related book a sequel and any set of three related books a trilogy—sometimes to the surprise of the author. As the Gershwins would warn us, “It Ain’t Necessarily So.”
EDWARD M. LERNER worked in high tech for thirty years, as everything from engineer to senior vice president. He writes near-future techno-thrillers, most recently Fools’ Experiments and Small Miracles, and far-future space epics like the Fleet of Worlds series with colleague Larry Niven. Just out: Destroyer of Worlds. Ed blogs regularly at SF and Nonsense.